Satellite cell functional alterations following cutaneous burn in rats include an increase in their osteogenic potential

Background: Significant consequences of severe burn include skeletal muscle atrophy and heterotopic ossification (HO). The cellular mechanisms underlying either of these conditions are not known. Whether the functionality of satellite cells stem cells resident in skeletal muscle is affected by changes in circulatory factors following burn was determined to better understand their role in atrophy and HO. Materials and methods: Serum (20%) from sham-treated animals or burned animals (40% total body surface area full-thickness burn) was used to culture satellite cells isolated from either sham or burn animals. Satellite cells were separated based on fiber type (i.e., fast-twitch or slow-twitch in some cases). To gain greater insight into the potential role for satellite cells in controlling muscle mass following burn, the effect of serum taken from burn animals on satellite cell proliferation, migration, and myogenic differentiation was evaluated. Osteogenic differentiation was assessed to evaluate the potential of satellite cells to contribute to HO. Results: Burn serum (BS) increased the proliferative capacity of cells from fast-twitch muscle, and the migratory capacity of satellite cells taken from both fast- and slow-twitch muscles. BS increased both the myogenic and osteogenic differentiation of satellite cells taken from both sham and burn animals. Conclusions: The unexpected increase in myogenic functionality of satellite cells with BS is difficult to rectify, given the degree of atrophy that occurs. However, the increased osteogenic capacity of satellite cells with BS suggests they may play a role in burn-induced HO.